1. Field of the Invention
The invention relates in general to a transmission method for mobile communication messages, and more particularly to a method for transmitting a multimedia messaging service (MMS) message.
2. Description of the Related Art
Multimedia Message Service (MMS) is a type of message service. When a communication device transmits a multimedia message (or MMS message) to a mobile station, a message center established by operators relays the MMS message to the mobile station. MMS messages are messages that combine media contents of characters, sounds, pictures, and video clips. MMS are applied in various applications, such as multimedia greeting cards, name cards, presentations, and successive video-audio data. The protocol of MMS is an open standard drawn up by two important international mobile communication standard institutions, which are the third generation partnership project (3GPP) and wireless application protocol forum (WAP FORUM). Under cooperation of operators, mobile phone manufacturers, and other related companies or organizations, MMS has capability of cross-platform and cross-mobile-phone-brands.
In addition to mobile phones, a personal digital assistant (PDA), a computer, or e-mail software may also be used for transmitting MMS messages. Referring to FIG. 1, a mobile apparatus 100 is applied in a wireless communication network 10 that provides MMS service. In FIG. 1, the mobile apparatus 100 is a mobile station capable of receiving MMS messages and is used for retrieving MMS messages via a message center 130 via the wireless communication network 10. MMS messages received by the mobile apparatus 100 are from various transmission terminals via the message center 130. For example, another mobile station 120 in the wireless communication network 10 transmits MMS messages to the mobile apparatus 100. Another kind of transmission terminal, say, a mobile station located in another wireless communication network, such as a GPRS mobile station 140 in the GPRS network 300, also can transmit MMS messages to the mobile apparatus 100 via the message centers 150 and 130. Moreover, a computer 160 coupled to the Internet 20 also can transmit MMS messages to the mobile apparatus 100 via the message center 130 coupled to the Internet 20.
When message centers receive a MMS message to be transmitted to a receiver terminal, the message center transmits a notification to the receiver terminal to notify that there is arrival of the MMS message. The notification includes information related to the MMS message, such as a sender (FROM), a receiver (TO), a subject, a size, and a retrieval address of the MMS message.
FIG. 2A illustrates a procedure for a mobile apparatus 100 to retrieve a MMS message from a message center 130 (marked as MMSC). When the message center 130 receives a MMS message from a sender, the message center 130 transmits a notification 210 to the mobile apparatus 100. On receiving the notification a response procedure 220 of the mobile apparatus 100 is executed for determining whether to retrieve the MMS message identified by the notification. When the mobile apparatus 100 determines to receive the MMS message, the mobile apparatus 100 transmits a GET request 230 to the MMS center for downloading the MMS message. The GET request 230 has many formats, such as a GET request of a hypertext transfer protocol (HTTP), or a GET request of a WAP session protocol (WSP). When the message center 130 receives the GET request 230, the message center 130 transmits the MMS message packaged into one or more response messages 240. When the whole MMS message is received, the mobile apparatus 100 transmits a notify response to the message center 130 to complete the task of transmitting the MMS message.
According to the size of the MMS message identified in the notification transmitted from the MMS center 130, the response procedure 220 of the mobile apparatus 100 determines whether to download the MMS message, that is, to determine whether to transmit a GET request 230 to the message center 130. Two conventional methods for retrieving the MMS message are introduced in the following description, which respectively use two different response procedures 220 to download MMS messages.
If the size of a MMS message identified in the notification is smaller than a predetermined acceptable value, such as 30 KB, usually a default value set by users, the message body of the MMS message is downloaded automatically. Such approach is called a message method of “immediate retrieval”; An example of using the “immediate retrieval” method is Nokia 6610 mobile phones. FIG. 2B is a flowchart illustrating the notification response procedure 220. As shown in step 221, a notification is received by the mobile apparatus 100. In step 222, the message body size identified in the notification is compared with a default value set by users. If the message body has a size smaller than the user set value, a GET request is transmitted to the message center (step 228). As shown in step 229, the mobile apparatus 100 starts to wait for the response message from the message center. By using this method, a user does not need to do any thing when the mobile apparatus is downloading MMS messages. If the MMS message is small, it is convenient for a user to use the “immediate retrieval” method.
Another conventional method for retrieving MMS messages is a message method of “delayed retrieval”, in which a user to receive a MMS message needs to confirm whether to download the MMS message each time. The user determines whether to download the MMS message according to information provided in the notification, for example, the size of the MMS message and sender. Referring to FIG. 2B, in step 222, if the size of message body in the notification is not smaller than the user-set value, the reception terminal sends a notify response to the message center (step 223). Then, the mobile apparatus performs a waiting assurance procedure (step 225). In the waiting assurance procedure, the step 226 is performed to determine whether the user wants to retrieve the multimedia message. If so, the mobile apparatus transmits a GET request to the message center (step 228). Next, the response message is transmitted from the message center to the mobile apparatus (step 229).
In addition to the two methods mentioned above, the size of MMS message identified in the notification is usually the critical reference for most users in determining whether to download the MMS message. However, these methods have potential serious security issues. For example, an unstable MMS center may generate a notification identifying an incorrect message size smaller than an actual MMS message. Furthermore, those with malicious intentions, or computer hackers, may fabricate and transmit a notification identifying an incorrect message size. Garbage advertisement letters are another sort of MMS message misuse. Besides, if the actual size of a MMS message is larger than that identified in associated notification, a user may waste lots of unexpected money in downloading massive MMS messages under deceit.
Due to incorrect notification mentioned above, even if the mobile apparatus is configured to adopt the “immediate retrieval” message method and the maximum size of a MMS message to be automatically downloaded is given, the mobile apparatus may still download a MMS message of larger size, if the notification provides a fake size. In the same situation, even if the user is inquired, each time, about whether to download a MMS messages under the message method of “delayed retrieval”, a MMS message of larger size may still be downloaded.
The problems mentioned above cause lots of trouble. Users waste time and money for improper messages. In conventional MMS technology, associated potential security issues are not well discussed and solved. To make MMS service more convenient and helpful for human life, it is important to find a better and effective way to manipulate MMS messages.